1. Field of the Invention
The present invention relates to a hole puncher and reinforcer for positioning adhesive tape over a sheet of material to be reinforced, punching a hole in both the tape and the sheet, and shearing off the punched tape section.
2. Description of the Prior Art
Various machines have been advanced in the prior art for punching holes in looseleaf sheets of paper and contemporaneously applying reinforcing material around the punched holes.
In the apparatus of U.S. Pat. No. 3,898,919, annular disks are punched out of pressure sensitive adhesive tape and pressed around looseleaf sheet holes which are to be reinforced. The web of punched or waste tape passes over a take-up roll which is driven to pull fresh tape through the punch mechanism. Tape wastage is unavoidable because the waste tape web is an integral part of the feed means.
In U.S. Pat. No. 2,353,232 the puncher and reinforcer require use of dry adhesive tape. Disks punched from the tape have to be moistened before being pressed onto the looseleaf sheet. The inability of the machine to handle pressure sensitive tape is a serious shortcoming.
U.S. Pat. No. 2,441,821 teaches an apparatus having an apertured spring plate over which a paper sheet is positioned. Pressure sensitive tape is fed beneath the spring plate, with its adhesive or sticky side up. The tape feed mechanism is designed to avoid contact with the sticky side of the tape, the tape being fed by a pinwheel whose pins pierce through the nonadhesive side of the tape to advance it as the pinwheel rotates. The paper sheet is pressed downwardly by a die plate which adheres the paper sheet to the tape, and then shears off the adhered tape section. A punch next passes through the aperture in the spring to punch holes in both the sheet and the tape. A special idler roll is used to orient the sticky side of the tape away from the various feed surfaces for attachment to the underside of the paper sheet. This idler roll, the spring plate, and the pinwheel feed are all needed to isolate the feed surfaces from the sticky side of the tape, and all add to the complexity and expense of the apparatus.
U.S. Pat. No. 2,771,009 discloses a feed mechanism having grippers which temporarily hold the adhesive tape to advance it longitudinally. The grippers must disengage the tape to repeat each feeding cycle. Special separator members are required to enable such repetitive separation of the grippers from the sticky tape as it is advanced.
Thus, the punching and reinforcing machines of the prior art are either not designed to handle sticky adhesive tape, or the feed mechanisms they employ to deal with such tape are relatively complex and expensive to manufacture. Other machines are complicated by multiple punches, or are characterized by tape wastage.